Choosing a Neelam: A Clear Guide to Buying Blue Sapphire

Blue sapphire, Neelam to most of our customers, is the stone we are asked about most. It is also the stone with the most stories attached. Some of those stories are useful. Many are sales talk. Here is how to look at a Neelam calmly.

What a blue sapphire is

Sapphire is corundum, crystallised aluminium oxide. Traces of iron and titanium give it blue. It is hardness 9, second only to diamond among natural gems, which makes it one of the best choices for a ring worn every day. Ruby is the same mineral in red, and purple sapphire and yellow sapphire are its cousins in other colours.

Colour comes first

Colour drives most of a sapphire's value. Gemmologists break it into three parts.

Hue

Hue is the basic colour. Pure blue is the target. Many sapphires lean slightly violet or slightly green. A touch of violet is usually welcome. A strong green or grey tint lowers the price.

Tone

Tone is how light or dark the colour is. The most wanted sapphires sit in the medium to medium-dark range. Very light stones look pale and watery. Very dark ones look almost black indoors, sometimes called inky. Hold a stone away from a bright window and see whether the blue survives in ordinary room light.

Saturation

Saturation is the strength of the colour. A vivid stone looks rich and lively. A weak one looks greyish or dull. Two stones of the same tone can feel completely different because of saturation alone.

Look for colour zoning too. Sapphires often grow in bands, and a stone may show stripes of deeper and paler blue from the side. Good cutting hides this from the top. Some zoning is normal and does not mean a stone is fake.

Origin talk, without the hype

Sellers love origin names. They can tell you something, but they are not a grade of quality.

• Sri Lanka: long known for bright, medium blue stones, often lighter in tone and lively in sparkle. Most fine Neelam sold in South Asia over the past century came from here.
• Kashmir: the famous name. The classic mines produced for a short period in the late nineteenth and early twentieth centuries and very little since. A true Kashmir stone is rare and needs a serious lab's origin opinion. Treat the word "Kashmiri" in a market with polite scepticism.
• Madagascar: a major source since the 1990s, with a wide range from pale to deep blue. Some stones resemble Sri Lankan material closely.
• East Africa and elsewhere: Tanzania, Kenya, Nigeria and others produce many sapphires, often deeper and darker in tone, generally at friendlier prices.

Origin can only be judged by a laboratory, and even labs give it as an opinion. We list the origin we have for each stone and never more. A beautiful Madagascar stone is a better buy than a dull one with a famous label.

Heat treatment, explained plainly

Most sapphires on the world market have been heated. Heating is an old, stable and widely accepted practice. It can improve colour and dissolve fine needles of rutile that make a stone look cloudy. A heated sapphire is still a natural sapphire.

What matters is disclosure. Unheated stones with fine colour are rarer and cost more, so a seller should say what is known. Other treatments are a different matter. Beryllium diffusion and glass filling change a stone more deeply and should always be named. On our pages each stone shows its treatment status as recorded. Where it says "not tested", the stone has not been lab-tested for treatment and you are welcome to have it tested. Our guide to gem pricing covers how treatment affects value.

Clarity and cut

Sapphires usually have some inclusions. Fine silk, small crystals and healed fractures are normal. Look for stones without large cracks reaching the surface. A well cut sapphire returns light evenly across the top. A poorly cut one has a dead, see-through patch in the centre, called a window.

Sizes for rings

Sapphire is dense, so it looks a little smaller than you might expect for its weight.

• 1 to 2 ct: neat and discreet. Popular for women's rings and slim bands.
• 3 to 5 ct (roughly 3.3 to 5.5 ratti): the most common choice for men's rings. Clearly visible without being heavy.
• 6 ct and above: a bold stone. Prices per carat often climb at this size for good colour.

Measure the finger and check millimetres, not just weight. Our ring or pendant guide covers settings, and the ratti guide helps if you have been told a weight in ratti.

Tradition

In South Asian tradition Neelam is linked with Saturn, and many people wear it on the advice of an astrologer or an elder. Some families suggest wearing a new Neelam for a trial period first. We respect these customs and describe them as customs. We make no promises about what a stone will do, only about what it is.

If a deep blue is what you love but the budget is tight, look at blue topaz or tanzanite as honest alternatives. Browse our Neelam collection when you are ready.